Flaring shaped Seawall was adopted as the Osako port in Kurahashi-cho for the first time in the country in consideration of low height, scene nature, preservation of sands, and economical efficiency, etc. The height of flaring shaped seawall was decided to be +6.0m using the wave overtopping rate presumption diagram ofit. Although we conducted the two-dimensional wave tank model in the proposal section and the wave overtopping rate (0.0002m3/m/s) checked that it was1/50 of the permissible value, the breaking wave pressure became large shockingly, it was about five times the Goda equation wave pressure. Structure of flaringshaped seawall was made into the composite construction of steel and concrete. The structure design was performed in finite-element analysis by making this shockingly breaking wave load into static load and was able to be designed rationally. Since composite structure was adopted, construction of flaring shaped seawallwas able to be performed very easily.
